This invention relates to the art of sensing the electrical conductivity of fluid, and more particularly to a new and improved apparatus for sensing and signalling the presence of liquid having a predetermined electrical conductivity.
One area of use of the present invention is detonating an electro explosive device of a release mechanism for uncoupling a parachute canopy upon landing in water, although the principles of the present invention can be variously applied. An important consideration in the design of such release mechanisms is preventing accidental detonation arising, for example, from exposure of the sensor to rain. On the other hand, once the valid condition for detonation is satisfied, i.e. landing in a body of water, it is desirable to have the detonation occur as rapidly as possible. In addition to providing specific measures to accomplish the foregoing, it would be highly desirable to provide for use with such release mechanisms conductivity sensing apparatus having the smallest possible number of components to enhance the probability of achieving the highest possible reliability. Also, it would be highly advantageous to provide such conductivity sensing apparatus wherein the electrical integrity of the load, for example the electro explosive device, can be tested with standard equipment and procedures.